Contributions of Glaciers to Sea Level Rise Over the Past Half-Century

The largest source of eustatic sea level rise during the past century is mass loss from land ice (ice sheets and glaciers) through meltwater runoff and solid ice discharge to the oceans. Both glacier and ice sheets play an important role in sea level change; Ice sheets contain nearly all of the Earth’s land ice (>99% by volume) and will likely dictate changes in sea level rise over the next millennia, while glaciers only contain enough ice to raise global sea levels by 0.4-0.6 m if melted entirely. Even so, glaciers play a major role in present rates of sea level rise and will continue to do so into the next century and beyond.

We provide a robust estimate of long-term glacier mass changes for glacierized regions that lack published regional-scale geodetic estimates. These regions comprise 70% of the world’s glacier ice by area and, when combined with previously published regional estimates, will provide a nearly complete global (98% coverage) estimate of multi-decadal glacier contribution to sea level rise.